puffs_node.c revision 1.38
1/* $NetBSD: puffs_node.c,v 1.38 2018/02/08 09:05:20 dholland Exp $ */ 2 3/* 4 * Copyright (c) 2005, 2006, 2007 Antti Kantee. All Rights Reserved. 5 * 6 * Development of this software was supported by the 7 * Google Summer of Code program, the Ulla Tuominen Foundation 8 * and the Finnish Cultural Foundation. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 20 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 21 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 22 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 25 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32#include <sys/cdefs.h> 33__KERNEL_RCSID(0, "$NetBSD: puffs_node.c,v 1.38 2018/02/08 09:05:20 dholland Exp $"); 34 35#include <sys/param.h> 36#include <sys/hash.h> 37#include <sys/kmem.h> 38#include <sys/mount.h> 39#include <sys/namei.h> 40#include <sys/vnode.h> 41 42#include <uvm/uvm.h> 43 44#include <fs/puffs/puffs_msgif.h> 45#include <fs/puffs/puffs_sys.h> 46 47#include <miscfs/genfs/genfs_node.h> 48#include <miscfs/specfs/specdev.h> 49 50struct pool puffs_pnpool; 51struct pool puffs_vapool; 52 53/* 54 * Grab a vnode, initialize all the puffs-dependent stuff. 55 */ 56static int 57puffs_getvnode1(struct mount *mp, puffs_cookie_t ck, enum vtype type, 58 voff_t vsize, dev_t rdev, bool may_exist, struct vnode **vpp) 59{ 60 struct puffs_mount *pmp; 61 struct vnode *vp; 62 struct puffs_node *pnode; 63 int error; 64 65 pmp = MPTOPUFFSMP(mp); 66 67 if (type <= VNON || type >= VBAD) { 68 puffs_senderr(pmp, PUFFS_ERR_MAKENODE, EINVAL, 69 "bad node type", ck); 70 return EPROTO; 71 } 72 if (vsize == VSIZENOTSET) { 73 puffs_senderr(pmp, PUFFS_ERR_MAKENODE, EINVAL, 74 "VSIZENOTSET is not a valid size", ck); 75 return EPROTO; 76 } 77 78 for (;;) { 79 error = vcache_get(mp, &ck, sizeof(ck), &vp); 80 if (error) 81 return error; 82 mutex_enter(vp->v_interlock); 83 pnode = VPTOPP(vp); 84 if (pnode != NULL) 85 break; 86 mutex_exit(vp->v_interlock); 87 vrele(vp); 88 } 89 mutex_enter(&pnode->pn_mtx); 90 mutex_exit(vp->v_interlock); 91 92 /* 93 * Release and error out if caller wants a fresh vnode. 94 */ 95 if (vp->v_type != VNON && ! may_exist) { 96 mutex_exit(&pnode->pn_mtx); 97 vrele(vp); 98 return EEXIST; 99 } 100 101 *vpp = vp; 102 103 /* 104 * If fully initialized were done. 105 */ 106 if (vp->v_type != VNON) { 107 mutex_exit(&pnode->pn_mtx); 108 return 0; 109 } 110 111 /* 112 * Set type and finalize the initialisation. 113 */ 114 vp->v_type = type; 115 if (type == VCHR || type == VBLK) { 116 vp->v_op = puffs_specop_p; 117 spec_node_init(vp, rdev); 118 } else if (type == VFIFO) { 119 vp->v_op = puffs_fifoop_p; 120 } else if (vp->v_type == VREG) { 121 uvm_vnp_setsize(vp, vsize); 122 } 123 124 pnode->pn_serversize = vsize; 125 126 DPRINTF(("new vnode at %p, pnode %p, cookie %p\n", vp, 127 pnode, pnode->pn_cookie)); 128 129 mutex_exit(&pnode->pn_mtx); 130 131 return 0; 132} 133 134int 135puffs_getvnode(struct mount *mp, puffs_cookie_t ck, enum vtype type, 136 voff_t vsize, dev_t rdev, struct vnode **vpp) 137{ 138 139 return puffs_getvnode1(mp, ck, type, vsize, rdev, true, vpp); 140} 141 142/* new node creating for creative vop ops (create, symlink, mkdir, mknod) */ 143int 144puffs_newnode(struct mount *mp, struct vnode *dvp, struct vnode **vpp, 145 puffs_cookie_t ck, struct componentname *cnp, 146 enum vtype type, dev_t rdev) 147{ 148 struct puffs_mount *pmp = MPTOPUFFSMP(mp); 149 int error; 150 151 /* userspace probably has this as a NULL op */ 152 if (ck == NULL) 153 return EOPNOTSUPP; 154 155 /* 156 * Check for previous node with the same designation. 157 * Explicitly check the root node cookie, since it might be 158 * reclaimed from the kernel when this check is made. 159 */ 160 if (ck == pmp->pmp_root_cookie) { 161 puffs_senderr(pmp, PUFFS_ERR_MAKENODE, EEXIST, 162 "cookie exists", ck); 163 return EPROTO; 164 } 165 166 KASSERT(curlwp != uvm.pagedaemon_lwp); 167 168 error = puffs_getvnode1(dvp->v_mount, ck, type, 0, rdev, false, vpp); 169 if (error) { 170 if (error == EEXIST) { 171 puffs_senderr(pmp, PUFFS_ERR_MAKENODE, EEXIST, 172 "cookie exists", ck); 173 error = EPROTO; 174 } 175 return error; 176 } 177 178 if (PUFFS_USE_NAMECACHE(pmp)) 179 cache_enter(dvp, *vpp, cnp->cn_nameptr, cnp->cn_namelen, 180 cnp->cn_flags); 181 182 puffs_updatenode(VPTOPP(dvp), PUFFS_UPDATECTIME|PUFFS_UPDATEMTIME, 0); 183 184 return 0; 185} 186 187void 188puffs_putvnode(struct vnode *vp) 189{ 190 struct puffs_node *pnode; 191 192 pnode = VPTOPP(vp); 193 194 KASSERT(vp->v_tag == VT_PUFFS); 195 196 genfs_node_destroy(vp); 197 198 /* 199 * To interlock with puffs_getvnode1(). 200 */ 201 mutex_enter(vp->v_interlock); 202 vp->v_data = NULL; 203 mutex_exit(vp->v_interlock); 204 puffs_releasenode(pnode); 205} 206 207/* 208 * Make sure root vnode exists and reference it. Does NOT lock. 209 */ 210static int 211puffs_makeroot(struct puffs_mount *pmp) 212{ 213 struct vnode *vp; 214 int rv; 215 216 /* 217 * pmp_lock must be held if vref()'ing or vrele()'ing the 218 * root vnode. the latter is controlled by puffs_inactive(). 219 * 220 * pmp_root is set here and cleared in puffs_reclaim(). 221 */ 222 223 rv = puffs_getvnode(pmp->pmp_mp, pmp->pmp_root_cookie, 224 pmp->pmp_root_vtype, pmp->pmp_root_vsize, pmp->pmp_root_rdev, &vp); 225 if (rv != 0) 226 return rv; 227 228 mutex_enter(&pmp->pmp_lock); 229 if (pmp->pmp_root == NULL) 230 pmp->pmp_root = vp; 231 mutex_exit(&pmp->pmp_lock); 232 233 return 0; 234} 235 236/* 237 * Locate the in-kernel vnode based on the cookie received given 238 * from userspace. 239 * 240 * returns 0 on success. otherwise returns an errno or PUFFS_NOSUCHCOOKIE. 241 * 242 * returns PUFFS_NOSUCHCOOKIE if no vnode for the cookie is found. 243 */ 244int 245puffs_cookie2vnode(struct puffs_mount *pmp, puffs_cookie_t ck, 246 struct vnode **vpp) 247{ 248 int rv; 249 250 /* 251 * Handle root in a special manner, since we want to make sure 252 * pmp_root is properly set. 253 */ 254 if (ck == pmp->pmp_root_cookie) { 255 if ((rv = puffs_makeroot(pmp))) 256 return rv; 257 *vpp = pmp->pmp_root; 258 return 0; 259 } 260 261 rv = vcache_get(PMPTOMP(pmp), &ck, sizeof(ck), vpp); 262 if (rv != 0) 263 return rv; 264 mutex_enter((*vpp)->v_interlock); 265 if ((*vpp)->v_type == VNON) { 266 mutex_exit((*vpp)->v_interlock); 267 /* XXX vrele() calls VOP_INACTIVE() with VNON node */ 268 vrele(*vpp); 269 *vpp = NULL; 270 return PUFFS_NOSUCHCOOKIE; 271 } 272 mutex_exit((*vpp)->v_interlock); 273 274 return 0; 275} 276 277void 278puffs_updatenode(struct puffs_node *pn, int flags, voff_t size) 279{ 280 struct timespec ts; 281 282 if (flags == 0) 283 return; 284 285 nanotime(&ts); 286 287 if (flags & PUFFS_UPDATEATIME) { 288 pn->pn_mc_atime = ts; 289 pn->pn_stat |= PNODE_METACACHE_ATIME; 290 } 291 if (flags & PUFFS_UPDATECTIME) { 292 pn->pn_mc_ctime = ts; 293 pn->pn_stat |= PNODE_METACACHE_CTIME; 294 } 295 if (flags & PUFFS_UPDATEMTIME) { 296 pn->pn_mc_mtime = ts; 297 pn->pn_stat |= PNODE_METACACHE_MTIME; 298 } 299 if (flags & PUFFS_UPDATESIZE) { 300 pn->pn_mc_size = size; 301 pn->pn_stat |= PNODE_METACACHE_SIZE; 302 } 303} 304 305/* 306 * Add reference to node. 307 * mutex held on entry and return 308 */ 309void 310puffs_referencenode(struct puffs_node *pn) 311{ 312 313 KASSERT(mutex_owned(&pn->pn_mtx)); 314 pn->pn_refcount++; 315} 316 317/* 318 * Release pnode structure which dealing with references to the 319 * puffs_node instead of the vnode. Can't use vref()/vrele() on 320 * the vnode there, since that causes the lovely VOP_INACTIVE(), 321 * which in turn causes the lovely deadlock when called by the one 322 * who is supposed to handle it. 323 */ 324void 325puffs_releasenode(struct puffs_node *pn) 326{ 327 328 mutex_enter(&pn->pn_mtx); 329 if (--pn->pn_refcount == 0) { 330 mutex_exit(&pn->pn_mtx); 331 mutex_destroy(&pn->pn_mtx); 332 mutex_destroy(&pn->pn_sizemtx); 333 seldestroy(&pn->pn_sel); 334 if (pn->pn_va_cache != NULL) 335 pool_put(&puffs_vapool, pn->pn_va_cache); 336 pool_put(&puffs_pnpool, pn); 337 } else { 338 mutex_exit(&pn->pn_mtx); 339 } 340} 341